Origin. - The dried tuberous root of Aconitum Napellus L., collected in autumn, and yielding when assayed not less than 0.5 per cent. of aconitine, a plant about 40 inches (1M.) high, met with throughout the greater portion of Asia and Europe, mostly in mountainous regions.

Other species of Aconitum contain aconitine. Thus the Himalayan plant Aconitum ferox contains it, and a closely related alkaloid, pseucaconitine, while the Aconitum Japonicum contains japaconitine. Aconitine is chemically an acetyl benaconine.

Description and Properties. - From 2/5 to 4/5 inch (10-20 Mm.) thick at the crown, and from 2 to 3 inches (50-75 Mm.) long, with scars or fragments of radicals; dark brown externally, whitish internally; with a rather thick bark, the central axis about seven-rayed; without odor, taste at first sweetish, soon becoming acrid, and producing a sensation of tingling and numbness lasting for some time. It contains an acrid alkaloid, aconitine.

Dose. - 1/2-2 grains (0.03-0.12 Gm.) [1 grain (0.65 Gm.) U. S. P.]

Official Preparations

Fluidextractum Aconiti - Fluidextracti Aconiti - Fluidextract of Aconite. - Dose, 1/10-2 minims (0.006-0.12 Cc.) [1 minim (0.05 Cc), U. S. P.].

Tinctura Aconiti - Tincturae Aconiti - Tincture of Aconite (10 per cent.). -Dose, 1 - 15 minims (0.015-1 Cc.) [10 minims (0.6 Cc), U. S. P.].

Aconitina - Aconitinae - Aconitine. U. S. P.

Definition. - An alkaloid obtained from Aconite.

Description and Properties. - Colorless or white rhombic tables or prisms, odorless, permanent in the air, and producing in extremely diluted solutions a characteristic tingling sensation when brought in contact with the mucous membrane of the tongue or lips. The alkaloid itself should never be tasted, and its solution only when largely diluted, and then with the utmost caution. The chemical structure of aconitine is analogous to that of atropine and cocaine.

Very slightly soluble in water (1: 3200), much more so in alcohol (1: 22).

Aconitine was formerly in the U. S. Pharmacopoeia, but was dropped in 1880, owing to the variable composition of the article then on the market. At present there are on the market, in addition to the crystalline aconitine, an amorphous aconitine and an eclectic "aconitin." The greatest caution should be observed not to confuse these preparations, as they differ considerably in composition.

Aconitine is the most powerful drug in the Pharmacopoeia; death is reported to have resulted from 0.5 milligramme (1/128 grain).

Dose. - Average dose: 0.00015 Gm. = 0.15 milligramme (1/400 grain) (U. S. P.).

Unofficial Preparation

Oleatum Aconitinae - Oleati Aconitlnae - Oleate of Aconite.- A 2 per cent.

solution of Aconitine in Oleic Acid. For external use. (N. F.)

Antagonists and Incompatibles. - Digitalis and other cardiac stimulants, including atropine and ether, antagonize the action of aconite.

Synergists. - All members of the group and cold enhance the action of the drug.

Physiological Action. - Externally and Locally. - Applied to mucous membranes or to the skin for any length of time, aconite first stimulates and then depresses the ends of the sensory nerves, producing respectively tingling, numbness, and local anesthesia.

Internally. - Digestive System. - Except when given in very dilute solutions, aconite produces tingling and numbness of the lips and mouth, with increased secretion from the salivary glands. Large doses cause great irritation, together with a sense of constriction in the fauces. Anesthesia to taste is also produced.

Under normal conditions of the stomach aconite may act upon that organ as a sedative, augmenting its secretions. Large doses may occasion pain, nausea, and vomiting.

Circulatory System. - Aconite causes a marked slowing of the heart's action, due to stimulation of the vagus center in the medulla. Following the slowing of the heart, due to vagus action, aconite has a direct action on the heart-muscle, increasing its irritability, causing it to become very rapid and weak, eventually occasioning delirium cordis through overstimulation. Death may occur from cardiac paralysis, the heart being arrested in diastole. The arterioles are at first contracted, owing to stimulation of the vasomotor center in the medulla; but a marked diminution in the force of the ventricular systole brings about a great decrease of blood-pressure. In poisoning there are vessel dilatation and great loss of blood-pressure.

Nervous System. - Moderate or even large doses have little or no effect on the cerebral centers. The main action of aconite in the nervous system is on the medulla. Here there is stimulation followed by depression. Excessive doses of aconite cause a slight stimulation of the sensory nerve-endings, finally followed by depression, the muscles passing into a state of paralysis, probably occasioned by direct action upon the muscle-tissue.

Respiratory System. - The respiration is slowed by moderate doses; under large doses it is rendered both shallow and slow. The breathing is retarded, because the peripheral endings of the vagi distributed to the lungs are depressed. Under large doses there is depression of the respiratory center, paralysis of which is occasioned by lethal amounts.

Temperature. - Aconite is alleged to be a decided antipyretic, the reduction of temperature being due to various causes: (1) The slowing of the circulation, diminishing the metabolism; (2) the peripheral action of aconite, causing dilatation of the cutaneous blood-vessels; (3) the depressing action of the drug upon all muscle-tissue.

Eye.- Toxic amounts of the drug have produced mydriasis, misty vision, and diplopia.

Absorption and Elimination. - Aconite is rapidly absorbed, but its channels of elimination are not definitely known, although it is probably excreted by the kidneys, and to some extent by the skin, the drug acting as a mild diaphoretic.

Untoward Action. - Besides the symptoms described under "Poisoning," there have been observed pustular and erythematous eruptions, vertigo, and dimness of vision.

Poisoning. - The first effect of toxic doses is to cause marked tingling of the tongue and lips, which sensation soon extends to the fingers and may even affect the entire cutaneous surface. There is extreme muscular weakness, particularly noticeable in the lower extremities. Salivation, excessive cold clammy perspiration, nausea, vomiting, diarrhea, and pain in the stomach occur. The pulse, at first slow and weak (down to 40), soon becomes rapid and almost imperceptible. The respirations are quite feeble and shallow, being at times reduced to 10-12 to the minute, and there may be marked dyspnea.

The countenance is anxious and the skin pallid, cold, and covered with sweat, with great reduction of temperature. These symptoms are accompanied by dimness of vision, the pupils usually being widely dilated. Rarely there are present epileptiform convulsions.

Death may be postponed for some time, or it may rapidly follow a lethal dose. The minimum lethal dose of aconitine for adults is 1/50 grain (0.003 Gm.).

Treatment of Poisoning. - The patient should be placed in a horizontal position, better with the feet raised slighly. The stomach should be thoroughly evacuated; bodily heat should be maintained by external warmth; diffusible stimulants, such as ether, alcohol, and spirits of ammonia should be given. Caffeine is useful, but artificial respiration is of the greatest service.

Therapeutics. - Externally and Locally. - Whether locally applied or given internally aconite is an excellent remedy in neuralgias, particularly in tic douloureux. The tincture, aconite liniment, or an ointment of aconitine may be applied to the course of the affected nerve. The tincture of aconite frequently proves beneficial in herpes zoster, chilblain, pruritus, etc., and its extended application has even been recommended to allay the pain of chronic rheumatism.

Internally. - Aconite is an exceedingly efficacious remedy in many febrile diseases, particularly the sthenic fevers of children and those fevers resulting from inflammation, such as tonsillitis, laryngitis, pharyngitis, quinsy, etc. The drug seems to exert a peculiarly beneficial influence on mucous membranes, all acute inflammatory conditions of the throat, bronchial tubes, or intestinal canal - characterized by fever, a small, wiry pulse, and rapid cardiac action - being greatly improved by the remedy. Digitalin may be advantageously added to aconitine in these cases to steady the heart, veratrine to increase elimination, and strychnine arsenate to increase vitality.

As previously indicated, aconite is one of the most efficient sedatives in the irritative fevers of children. It is equally valuable in the first stage of pneumonia and in pleurisy, and is an invaluable adjunct to opium in the treatment of peritonitis.

Pericarditis is often favorably influenced by this drug, while it is also of great service in allaying nervous palpitation of the heart or that due to excessive cardiac hypertrophy.

The injection into the rectum of 8 or 10 minims (0.5-0.6 Cc.) of the tincture of aconite, while perhaps producing a slight prolapsus of the rectum, quickly affects an irritable stricture of the urethra, so that a catheter may be passed with little difficulty, although the operation may have been previously found impossible.

Probably there is no better combination to "break up a cold" than aconite and Dover's powder, the tincture of aconite, given at frequent intervals for a few hours, being followed, preferably at bedtime, with 8 or 10 grains (0.5-0.6 Gm.) of Dover's powder.

In sudden congestions from exposure to cold and wet, with consequent chills, headache, stoppage of menstruation, etc., the prompt use of aconite will generally restore the circulatory equilibrium and bring back the flow, averting a serious illness.

Aconite has been favorably recommended in the acute stages of cerebrospinal meningitis and as a cardiac sedative in aneurism.

Contraindications. - Aconite is always contraindicated in subacute or chronic conditions, or when the heart's action is weak. It is also intolerable in catarrhal conditions of the stomach.

Administration. - A good, reliable tincture is the best preparation for internal use. Moreover, better results are obtained by giving the drug in fraction of minim doses - from 1/10 to 2 minim (0.006-0.03 Cc.) in a teaspoonful of water every fifteen minutes -than by larger dosage. The most desirable influence of the drug appears to be realized by this method.